1. Field of the Invention
The present invention relates to a clutch cover assembly, more particularly to a clutch cover assembly having a clutch cover with integrally formed support portions for supporting a diaphragm spring.
2. Description of the Related Art
A clutch cover assembly is attached to an engine side flywheel for engaging and dis-engaging a clutch. The clutch cover assembly is mainly made up of a clutch cover, a pressure plate and a diaphragm spring.
The clutch cover is formed of a substantially disc-shaped plate member with a large-diameter center hole in the center thereof. The clutch cover is fixed to the flywheel at an outer peripheral portion thereof by bolts. The pressure plate is formed of an annular member disposed within the clutch cover and has a pressing surface which faces a frictional facing of a clutch disc.
The diaphragm spring is made up of an annular resilient portion and a plurality of lever portions that extend radially inwardly from the resilient portion. In the push type clutch cover assembly, the outer peripheral portion of the resilient portion of the diaphragm spring abuts against the pressure plate, and the inner peripheral portion thereof is supported by the clutch cover. A known mechanism for supporting the inner peripheral side of the annular resilient portion is made up of, for example, a plurality of stud pins disposed circumferentially and two wire rings which are supported by these stud pins and abut against both surface, of the resilient portion. Also, there is known a mechanism in which the stud pins are replaced by a plurality of bent tabs that extend integrally toward the inner peripheral portion of the clutch cover, and these tabs penetrate an oblong hole of the diaphragm spring and are then bent so as to support two wire rings.
Further, there is known a mechanism in which no wire ring disposed between the resilient portion of the diaphragm spring and the clutch cover is used. In this mechanism, the wire ring is replaced by a protrusion formed through press working which supports the resilient portion. The omission of one wire ring allows the number of parts as used to be reduced and the assembling workability to be improved.
In the conventional clutch cover assembly from which one wire ring is omitted, the hardness of the protrusion formed through the press working is insufficient and liable to be worn.